Update! After replacing both vvt acuators and "reset ecm" I averaged 28.4 mpg on the info center. I put about 400 miles on it today driving from Augusta Ga to Greenville SC to Gastonia NC back to Gafney SC then back to Ga. I had just over 3/4 tank before I left and ran
it to empty -14.6 gal to top it off around the corner from home! 93 octane

 

Had my HHR about a month now. When I fill up, the fuel indicator reads around 290 miles. Within a day of driving say, 30 miles.. Its down to saying around 180 miles. And the needle is just above half. What is going on???

 

You did not mention the type of driving you do. If it is all city (stop and go), or very much city, you are achieving just about the correct EPA mileage. For example.......290 miles divided by 14 gals (guessing) = 20 MPG.

Also, according to most automotive publications, and all the wonderful, knowledgeable, intelligent people on this forum......the largest reason for not obtaining acceptable gas mileage is because of the drivers habits (I concur).

Frankly, because you have only had your HHR for a month, you probably don't understand the simplicities of its operation. This car will use more gas than expected (and get less than the posted EPA MPG) if you drive it RELATIVELY hard. It gets reasonable mileage if you treat it a little more gently (possibly obtaining (in my case) more MPG than the EPA estimate.

I suggest you enter an Interstate highway and zero out the mileage. Lock the cruise control on 65 and drive for about an hour or more. You should see MPG somewhere around 29-35. If you witness less than that, under these conditions, you may have a mechanical issue with the car. If you see more than that....good for you...you have an exceptional vehicle. I also suggest you manually calculate (pencil and paper) the mileage to see if you have a reasonable correlation. I'm suggesting this because, after reviewing your other 2 posts, you appear to rely on the computer algorithms and the gauge, may in fact, be malfunctioning. And it appears that you have guessed at the numbers.


Oh and your comment of, ".....say, 30 miles.. Its down to saying 180 miles. And the needle is just about half."...... That just is not possible based on your provided numbers. 30 miles divided by 7 = 4 miles per gallon.

 

And because you did not respond to questions asked in the other threads that you participated in.......

Have you zeroed out your fuel mileage read-outs as suggested?

 

2007 HHR, 2.2L. 6000 ft elevation

E10 - 34mpg
E85 - 30
M60 - 27

 

2008 HHR LS 2.2L, 5-speed manual at about 500 ft elevation.
During the summer months, I routinely get 35mpg. I can even squeeze out 37-38 on the highway hypermiling around 60mph.
Winter is another story. I can average 30-32mpg on the highway at around 60mph. Combination of the colder air and the winter mix gas I think.

 

Has anyone else tried a gas additive called Mix-I-Go? From Bell Performance in Florida. I've used it on a few different cars and bikes, and it does seem to improve the fuel burn. After a few tank loads, your tailpipe has no more black carbon in it- just a light gray ash.
Performance improved, mileage slightly if you aren't lead-footing it. I live really close to work, so mileage low- lots of traffic too. BTW, I'm not endorsing the product.

 

This post just reminded me, since I do usually use more than one vehicle as a daily driver, I sometimes get mind numb or dislectsic and glance at the fuel guage and get "empty" and "full" mixed up. There are no letters just a dot and a circle, and yeah I know what they mean but sometimes......
I had a Sonoma GMC that was the same way and it had an odd 11 o clock to 5 position for the dots so I was confused a few times with it too...stress I guess.

 

This actually happened to my dad back when I had my HHR. I was letting him drive it for the first time right after I had bought it and he thought the fuel gauge was reading 3/4 of a tank when really it was reading 1/4 of a tank. I usually don't let my car get below 1/2 a tank before filling up, but the dealer I had bought it from didn't give you a free tank of gas for a used car purchase and I hadn't filled it up yet when he drove it.

 

Drove from Niagara Falls NY to Erie PA yesterday, almost 400 miles I drove route 5 a mix of 40 to 55 mph zones along the south shore of Lake Erie, 35 to 48 degrees in my 2.2 automatic with 185,000 miles, this is what my average showed on the DIC